Its a 305cid w/ 120k on it. It seems to have started when I was monkeying with the carb. But b4 I do anything, I wanna check here and see what ya'll think or recommend. I dont wanna be chasing my tail on this. 1) Could carb cause this? If so, why? And what adjustments should I make , go lean or go rich? 2) Could it be a fluke that it does it when I adj. carb and it is really something else, like timing? 3) If it is timing what is the correct timing for this? I appreciate any advice, suggestions, help or comments.